Excavator



FIG. 1 is a front view of an excavator showing our new design;

FIG. 2 is rear view thereof;

FIG. 3 is a top plan view thereof.

FIG. 4 is a bottom plan view thereof.

FIG. 5 is a left side view thereof; and,

FIG. 6 is a right side view thereof. 

The ornamental design for an excavator, as shown and described. 